Design: multinational cross-sectional caregiver-completed online survey using Rome V criteria
Population: 8,000 children aged 0-17 in China, Italy, Mexico and the USA
Primary outcome: prevalence of disorders of gut-brain interaction by category, country, sex and age
Effect: 28.0% overall (95% CI 27.0-29.0); lower 23.7%, upper 8.7%; 41% at ages 0-3 falling to 22% in adolescents

Caregivers of 8,000 children aged 0 to 17 in China, Italy, Mexico and the USA completed an online Rome V survey covering gastrointestinal symptoms, illness burden and comorbid conditions.

Twenty-eight per cent of children met criteria for a disorder of gut-brain interaction (95% CI 27.0-29.0). Lower disorders accounted for most of it at 23.7%, dominated by defecation and anorectal disorders at 20.2%; abdominal pain disorders were 4.4%. Upper disorders were 8.7%, mostly gastroduodenal at 6.6%. Prevalence fell sharply with age, from about 41% in children aged 0 to 3 to 22% in adolescents, and varied by country, highest in Mexico and lowest in China. Gastroduodenal and discomfort disorders were commoner in girls. The disorders were associated with anxiety, depression, functional disability, healthcare use and parental time spent coordinating care, most of all where upper and lower disorders overlapped.

A caregiver-completed online survey in four countries is not a prevalence estimate for anywhere else, and the country differences may reflect how symptoms are reported as much as how often they occur. What is solid is the burden signal, and its concentration in the overlap group: a child with both upper and lower symptoms is the one with the disability and the exhausted parent, and that combination is worth recognising as a distinct clinical problem rather than two coincident ones.

Ask about both upper and lower symptoms; the overlap group carried the most disability.
Defecation and anorectal disorders were by far the commonest, at 20.2%.
Screen for anxiety and depression in children presenting with functional gut symptoms.
Ask what the symptoms cost the parent in time and missed work - it is part of the burden.
Caregiver-reported survey data in four countries; prevalence does not transfer to India unchanged.

Why it matters

It names the overlap of upper and lower symptoms as the highest-burden group, which is not how these children are usually categorised.

The statistics, in plain English

Prevalence from a caregiver-completed online survey depends heavily on who agrees to answer and how symptoms are described, which is the most likely source of the four-country differences. The confidence interval around 28% is narrow because 8,000 is a large sample, but narrow intervals around a possibly biased estimate are precision, not accuracy.